1. Field of the Invention
This invention relates to gas turbines, more particularly to turbine rings, that is the component of the turbine itself which surrounds at least the rotor blades.
2. Summary of the Prior Art
French patents published under nos. 2 371 575, 2 540 937, 2 540 938, 2 540 939 describe various forms of turbine rings each comprising (1) an annular carrier secured to the interior of the turbine casing and (2) an annulus comprised at least partially of abradable material and secured in its turn to the interior of the annular carrier. In most of these previously proposed constructions, the annular carrier is of a metallic material, so that when the abradable material is a ceramic material, as a result of the substantial difference in the coefficients of expansion of metallic materials and ceramic materials the annulus of ceramic material must be built up of sectors independent of one another and interconnected by their respective ends in order to enable at the radius of the abradable annulus the matching of changes in the radius of the carrier annulus as a function of the different temperatures which the latter assumes during different operational ratings of the turbine. As a result the abradable annulus will not be subject to stresses which are incompatable with the mechanical strength of the ceramic material which constitute it.
An object of the present invention is to provide a turbine ring incorporating an improved coupling method between the sectors mounted on the annular carrier in order to reduce to a minimum the tensile stresses which ceramic materials cannot readily accommodate.